In a typical system for pneumatically conveying bulk particulate materials from a first site to a second site, there is provided a material feed receptacle located at the first site, a material receiving receptacle located at the second site, a transport line receiving material from the feed receptacle and guiding it to the receiving receptacle and means for injecting air under pressure into the transport line to impel the material fed therein. Such receptacles at either of such sites may consist of storage vessels, processing equipment and various other modes of transportation including truck bodies, railway cars and ship holds.
Often, when the operation of such a system is shut down, a certain amount of material remains in the transport line which may be undesirable. Such condition could result in a distortion of measured amounts of the material being conveyed, a possible degradation of the residual material, a settling of the material causing subsequent blockage of the transport line and depending upon the material being conveyed, a possible undue deterioration of the transport line. Accordingly, it is the principal object of the present invention to provide a system for pneumatically conveying bulk particulate materials in which residual material in the transport line thereof may be readily purged upon shutdown of the system.